1. Field of the Disclosure
The present invention relates to a display device which detects a touch optically, and more particularly to a method for auto angle setting of an infrared sensor module which senses a light and a display device having the same applied thereto.
2. Discussion of the Related Art
In general, a touch screen, one of interface types between a user and an information and communication device which uses various kinds of displays, is an input unit which enables interface with the device by touching a screen with a hand or a pen, personally.
Being a device that can be used by any one only by touching a button displayed on a display device with a finger, handling the touch screen conversationally and intuitively, the touch screen is applied to many fields, such as issuing machines in banks and public agencies, different medical apparatuses, tour and major facility guidance and traffic guidance.
In the touch screen, there are resistive type, capacitive type, ultrasonic wave type, infrared type, and so on depending on methods of perception.
Though above types have advantages different from one another, recently the infrared type touch screen is paid attention owing to a minimized pressure applied thereto, and convenience of arrangement.
In the meantime, a related art infrared type touch screen determines coordinates by trigonometric measurement with two sets of infrared sensors and a retro-reflective plate.
In detail, the related art infrared type touch screen has two infrared light sources and infrared sensors on an upper side of an outside of a display module and the retro-reflective plate at a third side.
In this case, the determination whether a touch is made or not is made by directing a light from the infrared light source to the retro-reflective plate to retro-reflect the light, and sensing the light shielded at the time of the touch to calculate an angle to perceive the touch.
However, since the infrared sensor in the related art infrared type touch screen is positioned on the outside of the display module, a position of the infrared sensor is liable to deviate from a normal position during transportation or fabrication of the display device, or by shaking in a case of a finished display device. Thus, if the infrared sensor is deviated, additional work and time is required for correction of the deviation before shipment, and the correction of the deviation is not possible after the shipment.
Thus, the related art infrared type touch screen has the following problems.
Before shipment of the related art infrared type touch screen, in order to prevent a touch coordinate determination error from taking place, a particular portion is touched at an initial state after assembly to store a compensation value for an angular deviation in an look-up table for performing a compensation algorithm to compensate the deviation of the infrared sensor. However, since this is an error correction limited to the initial state and the particular region, failing correction of the error taking place during use or after the initial error correction, the error causes inconvenience to the user.
And, a particular method of calculation of the compensation value for the angular deviation of the look-up table has no high reliability.